Recently, to enhance the visibility for a vehicle, research on a vehicle including a camera module system provided with a plurality of cameras installed on the outside of the vehicle to enable a driver or a passenger in the vehicle to check outside conditions of the vehicle has been carried out.
Moreover, such a vehicle is provided with a screen for displaying images received from the plurality of cameras on the interior of the vehicle through an optical module. In this regard, development of related devices for assisting in driving of the vehicle and improving convenience in use has become active.
Meanwhile, unlike the configuration of an optical module embedded in a cowl top cover or a dashboard of a vehicle, in the case of a subminiature projection optical module mounted in an A-pillar or B-pillar, there is a problem of low visibility because the size of an image projected onto a screen is small.
Furthermore, with regard to installation of such a subminiature projector, it is not easy to dispose the projector in an interior part of the vehicle and secure a space for configuration of a projection type optical module for projecting an image having a predetermined size sufficient to provide appropriate visibility.
Moreover, in the case of an image display apparatus including a plurality of image modules configured to project images onto a screen, there is a problem in that it is difficult to adjust images projected from two or more image modules.
As a conventional technology, a projection lens unit for a PICO projector is disclosed in Korean Patent Application No. 10-2008-0081806 (hereinafter, referred to as ‘Document 1’). The conventional projection lens unit includes a lens array formed of five sheets, a color synthesizing prism, a cover glass and an image panel.
However, in the case of the configuration of Document 1, it cannot solve a problem of difficulty in installation of an image display apparatus including a subminiature projector. Also, there is still a problem in that, when an image display apparatus including a plurality of image modules is installed, it is difficult to adjust images projected from the respective image modules.